Modern oral care implements such as toothbrushes are often formed as composite structures constructed of at least two different materials which are configured to form a head for supporting tooth cleaning elements and a handle having a gripping portion for holding with a user's hand and a sometimes narrower neck portion supporting the head. A body formed of a base material, typically a rigid or semi-rigid type polymeric material (e.g. polypropylene and others), constitutes the main structure of the toothbrush handle. A second material, often an elastomeric (e.g. thermoplastic elastomer or TPE), is overlaid on various portions of the body for improved grip and ornamental appearance.
Toothbrushes are typically formed by injection molding. The body is first molded in a first operation from the base material, and then the second elastomeric material is overmolded onto body in a second operation to complete the toothbrush. Due to intricate applications and configurations of elastomers used in some toothbrush configurations, proper distribution of the fluidic elastomer to various surfaces on the base structure body in the second molding process presents a challenge to find the most cost-effective injection and distribution approach. In addition, it is further desirable to minimize the amount of base material used to fabricate the body for cost saving reasons.
An improved toothbrush construction and molding approach is therefore desired.